Gloria Deo 愿荣耀归上帝

Gloria Deo 愿荣耀归上帝

Silently, fossils speak from the earth, requiring translation and interpretation by humans who didn’t see when they were laid to rest.

Silently, fossils speak from the earth, requiring translation and interpretation by humans who didn’t see when they were laid to rest.

Beetle bling: The shiny blue scales of a weevil are still visible in a fossil after 49 million years, New Scientist claimed.

Tar pit puzzle: “The La Brea Tar Pits have stirred the imaginations of scientists and the public alike for over a century,” Science Daily writes. “But the

amount of time it took for ancient animals to become buried

in asphalt after enduring their gruesome deaths has

remained a mystery

.” Researchers found insect traces on the sesamoid bones and phalanges of herbivores, leading them to conclude the carcasses were exposed to the air for 17–20 weeks. Surprisingly, “Although

carnivorans vastly outnumber the amount of mammalian herbivorans

excavated from the tar pits,

no insect damage was found on their bones

.” Science Now’s coverage included this typo: “fossils like this 35,000-foot bone of a prehistoric horse,” probably intending 35,000 years, not 35,000 feet; that would be a pretty big horse otherwise. The original paper is in PLoS One.

Tar pit puzzle: “The La Brea Tar Pits have stirred the imaginations of scientists and the public alike for over a century,” Science Daily writes. “But the

amount of time it took for ancient animals to become buried

in asphalt after enduring their gruesome deaths has

remained a mystery

.” Researchers found insect traces on the sesamoid bones and phalanges of herbivores, leading them to conclude the carcasses were exposed to the air for 17–20 weeks. Surprisingly, “Although

carnivorans vastly outnumber the amount of mammalian herbivorans

excavated from the tar pits,

no insect damage was found on their bones

.” Science Now’s coverage included this typo: “fossils like this 35,000-foot bone of a prehistoric horse,” probably intending 35,000 years, not 35,000 feet; that would be a pretty big horse otherwise. The original paper is in PLoS One.

Transitional fleas: “Fleas are a group of highly specialized blood-feeding

ectoparasites whose early evolutionary history is poorly known

,” begins a paper in Current Biology by paleontologists from Russia, China and London. They claim to have found Cretaceous fossils that “greatly improves our understanding of the morphological

transition

to the

highly specialized body plan

of extant fleas.” The claim they are transitional relates primarily to gonad size, body size, and patterns of stiff body hairs. Since they have all the flea parts, though, the fossils could represent greater diversity in the past: “The new fossils, in conjunction with previous discoveries,

highlight a broad diversity of ectoparasitic insects

in the mid-Mesozoic.”

Transitional fleas: “Fleas are a group of highly specialized blood-feeding

ectoparasites whose early evolutionary history is poorly known

,” begins a paper in Current Biology by paleontologists from Russia, China and London. They claim to have found Cretaceous fossils that “greatly improves our understanding of the morphological

transition

to the

highly specialized body plan

of extant fleas.” The claim they are transitional relates primarily to gonad size, body size, and patterns of stiff body hairs. Since they have all the flea parts, though, the fossils could represent greater diversity in the past: “The new fossils, in conjunction with previous discoveries,

highlight a broad diversity of ectoparasitic insects

in the mid-Mesozoic.”

Transitional limbs: According to Science Daily, Yale scientists studied living mudskippers and salamanders to infer the evolutionary transition to land-based locomotion.

Transitional limbs: According to Science Daily, Yale scientists studied living mudskippers and salamanders to infer the evolutionary transition to land-based locomotion.

Why did animals with limbs win the race to invade land

over those with fins? A new study comparing the

forces acting on fins

of mudskipper fish and on the

forelimbs of tiger salamanders

can now be used to analyze early fossils that spanned

the water-to-land transition

in

tetrapod evolution

, and further understand their capability to move on land.

They measured the forces on limbs and fins of the living animals, thinking it would help explain the motions of the dead:

Sandy Kawano said: “

The transition from fins to limbs marks the most dramatic change

in orientation of the locomotor forces from contact with the ground. Using these data

we can now evaluate the locomotor capabilities of numerous important fossil taxa

that spanned the water-to-land transition in tetrapod evolution.

We hypothesise

that the medial orientation of the

forces

on pectoral fins

would result in unreasonably high bone stresses in early amphibious fish with fins

, which would explain

why the evolutionary invasion of land

by vertebrates

was accomplished instead by tetrapods with limbs with digits.

”

Sandy Kawano said: “

The transition from fins to limbs marks the most dramatic change

in orientation of the locomotor forces from contact with the ground. Using these data

we can now evaluate the locomotor capabilities of numerous important fossil taxa

that spanned the water-to-land transition in tetrapod evolution.

We hypothesise

that the medial orientation of the

forces

on pectoral fins

would result in unreasonably high bone stresses in early amphibious fish with fins